All about Yam on The Worldwide Gourmet

Etymology
From the Spanish "iñame" dating from 1515, derived from the African "nyami"

Did you know that arrowroot is a starch obtained from yams?

Yams are the traditional dish of West Indian and Nigerian cuisine, an ingredient in Indian fritters flavoured with coriander and ginger and a treat for North Americans

Nutritional Values

Yams, one of the important staple food crops of the tropics, are particularly important in Africa which accounts for about 95 % of world production. Nutritionally they are rich in carbohydrate (28 g) and are valuable sources of certain vitamins; they also contain 1.5-3.9 % protein.

Calories: 120
Water: 74%
Fats: 0.2 g
A 125 g portion provides 25% of the required daily intake of vitamin C.

Buying
look for large tubers with no wrinkles, soft spots or bruises

Storing

like potatoes, yams can be stored in a cool dark place for several months; however after a few months the starch has a tendency to turn to sugar and the yams are no longer recommended;
sensitive to cold, yams don't tolerate temperatures below 10° C (50° F) very well

Preparation

peel the yams (except small ones);
remove the stringy layer of flesh directly under the skin;
rinse in hot water (important) to remove the starch
use as you would potatoes

Use
Starchier than potatoes, yams cook more quickly and can be eaten raw.

Sautéed in a wok, yams stay crunchy and make an excellent substitute in recipes that call for water chestnuts.

Microwave Cooking

Cut the yam into julienne strips and place in a saucepan with 125 ml (1/2 cup) water;
cover and let cook for 8 to 9 minutes on high power;
serve drizzled with honey, butter, etc.